Recurrence of Pulmonary Arteriovenous Malformation after Embolization in Patients with Pulmonary Hypertension.

PURPOSE: To evaluate the correlation between pulmonary hypertension (PH) and recurrence of pulmonary arteriovenous malformation (PAVM) after embolization. MATERIALS AND METHODS: With institutional review board (IRB) approval, the records of 377 patients with PAVMs evaluated at a single hereditary hemorrhagic telangiectasia (HHT) center of excellence between January 1, 2013, and September 10, 2023, were retrospectively reviewed. PAVMs embolized during this time period were evaluated for recurrence. Patients and PAVMs not treated during this time period were excluded. Growth of previously untreated PAVMs was not considered recurrence. Patients without chest computed tomography (CT) follow-up were excluded. General demographics, HHT status as defined by genetic testing or Curacao criteria, presence of PH, history of smoking, anemia, and hepatic arteriovenous malformations (AVMs) were documented. Odds ratio (OR) was calculated and stratified analysis was performed to assay the correlation between PAVM recurrence, PH, and possible confounders. RESULTS: A total of 151 patients with PAVMs were treated during the study period, including 438 PAVMs, for which follow-up was available. This included 106 patients with definite, 31 with doubtful, and 14 with possible HHT. The presence of PH was significantly associated with PAVM recurrence both by patient (OR, 8.13; 95% CI, 3.50-19.67) and by lesion (OR, 4.07; 95% CI, 2.14-7.91). Multivariate analysis demonstrated that this correlation was independent of several variables including HHT status, smoking history, presence of hepatic AVMs, and anemia. CONCLUSIONS: There is a high correlation between PH and PAVM recurrence, suspected to be due to high pulmonary artery pressures causing recanalization. PH may suggest the need for shorter surveillance intervals.

Uterine arteriovenous malformation: a case report with proposal for pathogenesis.

Uterine arteriovenous malformation (UAM) is a rare medical condition. Even though UAM can cause abnormal and life-threatening uterine hemorrhage, there is no consensus on the clinical guideline on its treatments, most likely due to its low incidence, unknown etiology, and distinct fertility demands by different patients. Here, we present one elderly woman with uncommon UAM. We first discuss our experience regarding the diagnoses and treatments of UAM and then propose a hypothesis for the pathogenesis of UAM.

Arteriovenous malformations as a presenting sign of PTEN hamartoma tumor syndrome: A case series.

High-flow vascular malformations have been associated with multiple syndromes including capillary malformation-arteriovenous malformation (CM-AVM) syndrome, hereditary hemorrhagic telangiectasia syndrome, and less commonly, phosphatase and tensin homolog hamartoma tumor syndrome (PHTS). We present a series of three patients with clinically challenging complex AVMs who were found to have underlying PHTS. In all patients, diagnosis was delayed, and the presence of the AVM prompted sampling and genetic testing for PHTS in the absence of other clinical features of the condition. This series highlights the importance of screening for PHTS in the setting of high-flow vascular malformations.

A Rare Case of Cervical Spinal Arteriovenous Malformation: A Case Report.

Arteriovenous malformation (AVM) is an abnormal connection of vasculature resulting in capillary bed bypassing and leading to neurological deterioration and high risk of bleeding. Intramedullary AVMs in the cervical spinal cord are rare and require precise diagnostics and treatment. We present a clinical case of recurrent AVMs in a 28-year-old Caucasian female with sudden and severe neck pain and variable neurological symptoms along with current diagnostic and treatment modalities. Conservative treatment was partially effective. MRI and DSA confirmed AVMs at C4 level with subsequent several endovascular treatment sessions at the age of 15 and 24 with mild neurological improvement. Afterwards the patient underwent rehabilitation with minor neurological improvement. This case highlights the clinical progression and treatment of AVMs along with showcasing current pathophysiology, classification, and imaging.

Comparison of Transthoracic Contrast Echocardiography with High-Resolution Chest CT after Embolization of Pulmonary Arteriovenous Malformation.

PURPOSE: To compare postembolotherapy follow-up graded transthoracic contrast echocardiography (TTCE) and high-resolution computed tomography (CT) of the chest and to evaluate the use of graded TTCE in the early postembolic period. MATERIALS AND METHODS: Thirty-five patients (6 men and 29 women; mean age, 56 years; range, 27-78 years) presenting for postembolotherapy follow-up between 2017 and 2021 with concurrent high-resolution CT and graded TTCE were analyzed retrospectively. Untreated pulmonary arteriovenous malformations (PAVMs) with a feeding artery of ≥2 mm were considered treatable. RESULTS: Ninety-four percent of patients (33 of 35) did not have treatable PAVMs on high-resolution CT. TTCE was negative for shunts (Grade 0) in 34% of patients (n = 12). Of patients with a TTCE positive for shunts (23 of 35, 66%), 83% had a Grade 1 shunt, 13% had a Grade 2 shunt, and 4% had a Grade 3 shunt. No patient with a Grade 0 or 1 shunt had a treatable PAVM on high-resolution CT. Of the 2 patients with PAVMs requiring treatment, one had a Grade 2 shunt and one had a Grade 3 shunt. TTCE grade was significantly associated with the presence of a treatable PAVM on high-resolution CT (P < .01). CONCLUSIONS: Graded TTCE predicts the need for repeat embolotherapy and does so reliably in the early postembolotherapy period. This suggests that graded TTCE can be utilized in the postembolotherapy period for surveillance, which has the potential to lead to a decrease in cumulative radiation in this patient population.

Neurologic Complications in Hereditary Hemorrhagic Telangiectasia with Pulmonary Arteriovenous Malformations: A Systematic Review.

BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant multi-organ condition occurring with a 1 in 3800 prevalence in Alberta. This genetic disorder leads to vascular malformations in different organs including the lungs and brain, commonly affecting pulmonary vasculature leading to pulmonary arteriovenous malformations (PAVMs). PAVMs lead to right-to-left shunts, which may be associated with neurologic complications. We aimed to evaluate and summarize the reported neurologic manifestations of individuals with HHT with pre-existing PAVMs. METHODS: We performed a qualitative systematic review to determine available literature on neurological complications among patients with PAVMs and HHT. Published studies included observational studies, case studies, prospective studies, and cohort studies including search terms HHT, PAVMs, and various neurologic complications using MEDLINE and EMBASE. RESULTS: A total of 449 manuscripts were extracted including some duplicates of titles, abstracts, and text which were screened. Following this, 23 publications were identified for inclusion in the analysis. Most were case reports (n = 15). PAVMs were addressed in all these articles in association with various neurological conditions ranging from cerebral abscess, ischemic stroke, hemorrhagic stroke, embolic stroke, and migraines. CONCLUSION: Although HHT patients with PAVMs are at risk for a variety of neurological complications compared to those without PAVMs, the quality and volume of evidence characterizing this association is low. Individuals with PAVMs have a high prevalence of neurological manifestations such as cerebral abscess, transient ischemic attack, cerebral embolism, hemorrhage, and stroke. Mitigating stroke risk by implementing proper standardized screening techniques for PAVMs is invaluable in preventing increased mortality.

Gastrointestinal bleeding in patients with continuous-flow left ventricular assist devices: A comprehensive review.

BACKGROUND: Gastrointestinal bleeding is a major cause of morbidity that plagues the quality of life of patients supported on contemporary continuous-flow left ventricular assist devices (CF-LVADs). Despite benefits in survival and the nearly 50% reduction in complications provided by CF-LVADs, bleeding remains one of the most frequent adverse events with CF-LVAD implants. The CF-LVADs cause an increased risk of bleeding mainly due to the activation of the coagulation cascade. METHODS: A literature search was done using PubMed and Google Scholar from Inception to February 2022. Qualitative analyses of the articles retrieved were used to construct this review. This review attempts to provide a comprehensive summary of the epidemiology, pathophysiology, risk stratification, and management of gastrointestinal bleeding as a complication of CF-LVAD as well as propose an algorithm for diagnosis and treatment. RESULTS: Bleeding can occur at different sites in the gastrointestinal tract, the most common underlying pathology being arteriovenous malformations located in the upper gastrointestinal tract The increased prevalence of gastrointestinal (GI) bleeding in CF-LVAD patients has been attributed to the physiology of the LVAD itself, the use of anticoagulants, as well as patient comorbidities. Management involves pharmacologic and nonpharmacologic strategies. CONCLUSIONS: CF-LVAD-supported patients have a significant risk of GI bleeding that is mainly caused by arteriovenous malformations located in the upper GI tract. The increased prevalence of GI bleeding in CF-LVAD patients is attributed to several etiologies that include factors attributed to the device itself and extrinsic factors such as the use of anticoagulation.

Iatrogenic arteriovenous fistula in an infant mimicking an arteriovenous malformation.

We report the case of a 12-month-old infant who presented with progressive lower limb enlargement associated with erythema mimicking an arteriovenous malformation. Computed tomography confirmed an arteriovenous fistula (AVF) between the deep femoral artery and the common femoral vein. This case describes the unique clinical and imaging findings of iatrogenic AVF and contrasts them with other congenital vascular entities.

Endovascular Treatment Failure of Renal Arteriovenous Malformation due to an Extrarenal Feeding Artery: A Case Report.

Renal arteriovenous malformation (RAVM) is a rare pathology. It may present with heamturia, hypertension, and congestive heart failure. Digital subtraction angiography (DSA) is the standard diagnostic choice, and endovascular embolization is a preferred procedure of management in most cases. The feeding branches of RAVM are reported to originate from renal arteries. In this report, a 43-year-old female with recurrent massive hematuria and left flank pain was described. Renal angiography revealed double renal arteries supplying the left kidney and multiple renal arteriovenous fistula formation around the renal pelvis. Embolization with coils and gelfoam was performed after which her hematuria subsided. One month later, the patient was readmitted to our hospital due to the relapse of massive hematuria following heavy physical activities. DSA found another feeding artery of the RAVM originating from the aorta around the 4th lumbar vertebra. After embolization of this arterial feeder, hematuria settled. There was no recurrence during a 10-month follow-up. To our knowledge, this is the first case of RAVM with an extrarenal feeding artery, and omission of this scenario can lead to treatment failure.

Targeted embolisation for coexisting conus medullaris arteriovenous malformation and cauda equina arteriovenous fistulas with a varix on a shared drainer†.

BACKGROUND: The coexistence of vascular malformations in the conus medullaris and cauda equina has been rarely reported, and the complex angioarchitecture in multiple arteriovenous lesions remains poorly understood. CASE DESCRIPTION: A 17-year-old woman presented with a sudden-onset, stepwise worsening of weakness and pain in the bilateral legs. Angiography revealed conus medullaris arteriovenous malformation and cauda equina arteriovenous fistulas. One of the drainers was shared between the coexisting lesions and harboured a varix. Targeted embolisation of a fistulous point in the conus lesion was performed with precaution to prevent occluding the common drainage route, which led to symptom improvement with angiographical diminishment of the varix. CONCLUSIONS: Recognising that communications between drainers can be observed in multiple spinal arteriovenous lesions is important in facilitating a safe embolisation. Cautious assessment of angiogram with fusion images of cone-beam computed tomography and volumetric T2 magnetic resonance imaging can help in establishing the diagnosis and treatment strategy.

Intraspinal canal platform system for coil embolization of anterior spinal artery aneurysm associated with spinal cord arteriovenous malformation: a case report and literature review.

BACKGROUND: The prognosis for spinal artery aneurysms associated with spinal cord arteriovenous malformations (AVMs) is poor because of the high rupture rate of aneurysms. However, endovascular treatment remains technically difficult because the catheter system must be constructed via the small-caliber anterior spinal artery (ASA) or posterior spinal artery (PSA), which feeds functionally eloquent spinal cord. A 2.6F Carnelian HF-S microcatheter (Tokai Medical Products, Aichi, Japan) has been specifically designed to assist a 1.6F Carnelian MARVEL S microcatheter (Tokai Medical Products) as a small-profile 'platform catheter' close to the target lesion. Here we present a prenidal ASA aneurysm treated using a 2.6F Carnelian HF-S microcatheter as an intraspinal canal platform catheter and review related literature. CASE PRESENTATION: A 50-year-old man presented with a subarachnoid haemorrhage due to cervical spinal cord AVM. Diagnostic vertebral angiography revealed the AVM supplied by the PSA originated from the right C2 segmental artery and ASA arising from the right V4 segment. Superselective angiography for each feeder was achieved through a 2.6F Carnelian HF-S microcatheter, and a prenidal ASA aneurysm was diagnosed, which was clinically consistent with haemorrhagic origin. A 1.6F Carnelian MARVEL S microcatheter was cannulated into the aneurysm through the 2.6F Carnelian HF-S microcatheter positioned at the ASA. The aneurysm coiling was successfully performed without system instability or periprocedural complications. CONCLUSIONS: Only a few cases have described endovascular treatment for spinal artery aneurysms. To date, no reports have been published regarding the use of an intraspinal canal platform catheter to treat spinal artery aneurysms. A 2.6F Carnelian HF-S microcatheter served as a useful intraspinal canal platform catheter for coil embolization of the ASA aneurysm. This system can provide excellent accessibility and controllability for endovascular treatment of spinal artery lesions.

Hepatic involvement in hereditary hemorrhagic telangiectasia mimicking focal nodular hyperplasia.

Accurate diagnosis of hereditary hemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber disease, is important for reducing the risk of complications. Hepatic involvement in HHT is usually asymptomatic, but when present can cause noted morbidity and mortality. A 62-year-old woman presented with moderate upper-abdominal pain and tachycardia. A diagnosis of HHT was made based on the findings of hepatic involvement in a contrast-enhanced abdominal computed tomography (CT) scan, the presence of arteriovenous malformations (AVMs; a.k.a. telangiectasias) on mucocutaneous surfaces, and a history of recurrent epistaxis. Imaging methods are important diagnostic tools in patients suspected of having HHT.

Pulmonary arteriovenous malformations may be the only clinical criterion present in genetically confirmed hereditary haemorrhagic telangiectasia.

Pulmonary arteriovenous malformations (PAVMs) result in preventable complications demanding specialty care. Underlying hereditary haemorrhagic telangiectasia (HHT) can be identified by genetic testing, if the diagnosis is considered. Retrospectively reviewing 152 unrelated adults with genetically confirmed HHT due to ACVRL1, ENG or SMAD4, we found that only 104/152 (68%) met a clinical diagnosis of HHT with three Curaçao criteria. The genetic diagnostic rate was similar for patients with three (104/137, 76%) or one to two (48/71, 68%; p=0.25) criteria. Of 83 unrelated probands with PAVM(s) and genetically-confirmed HHT, 20/83 (24%) had few, if any, features of HHT. Enhanced clinical suspicion, as well as HHT genetic testing, is recommended if one or more PAVMs are present.

Loss of Endothelial Endoglin Promotes High-Output Heart Failure Through Peripheral Arteriovenous Shunting Driven by VEGF Signaling.

RATIONALE: ENG (endoglin) is a coreceptor for BMP (bone morphogenetic protein) 9/10 and is strongly expressed in endothelial cells. Mutations in ENG lead to the inherited vascular disorder hereditary hemorrhagic telangiectasia characterized by local telangiectases and larger arteriovenous malformations (AVMs); but how ENG functions to regulate the adult vasculature is not understood. OBJECTIVE: The goal of the work was to determine how ENG maintains vessel caliber in adult life to prevent AVM formation and thereby protect heart function. METHODS AND RESULTS: Genetic depletion of endothelial Eng in adult mice led to a significant reduction in mean aortic blood pressure. There was no evidence of hemorrhage, anemia, or AVMs in major organs to explain the reduced aortic pressure. However, large AVMs developed in the peripheral vasculature intimately associated with the pelvic cartilaginous symphysis-a noncapsulated cartilage with a naturally high endogenous expression of VEGF (vascular endothelial growth factor). The increased blood flow through these peripheral AVMs explained the drop in aortic blood pressure and led to increased cardiac preload, and high stroke volumes, ultimately resulting in high-output heart failure. Development of pelvic AVMs in this region of high VEGF expression occurred because loss of ENG in endothelial cells leads to increased sensitivity to VEGF and a hyperproliferative response. Development of AVMs and associated progression to high-output heart failure in the absence of endothelial ENG was attenuated by targeting VEGF signaling with an anti-VEGFR2 (VEGF receptor 2) antibody. CONCLUSIONS: ENG promotes the normal balance of VEGF signaling in quiescent endothelial cells to maintain vessel caliber-an essential function in conditions of increased VEGF expression such as local hypoxia or inflammation. In the absence of endothelial ENG, increased sensitivity to VEGF drives abnormal endothelial proliferation in local regions of high VEGF expression, leading to AVM formation and a rapid injurious impact on heart function.

Management of Acquired Uterine Arteriovenous Malformations Associated with Retained Products of Conception.

PURPOSE: To evaluate the efficacy and safety of different treatments for acquired uterine arteriovenous malformations associated with retained products of conception (UAVM-RPOC) and to investigate the role of uterine artery embolization (UAE) in acquired UAVM-RPOC. MATERIALS AND METHODS: This was a retrospective study of consecutive patients who were diagnosed with uterine arteriovenous malformation by ultrasound after recently terminated pregnancy. Forty-eight patients were included in this study and were divided into 2 groups (major and minor bleeding groups) according to vaginal bleeding. The treatments were analyzed between groups. Technical and clinical success rates of UAE were analyzed. RESULTS: Of the 48 patients, 11 patients were in the massive bleeding group and 37 were in the minor bleeding group. Five patients were referred for UAE in each group and UAE was a priority for patients with unstable hemodynamics (chi-square value = 5.524, P =.022). Conservative management, dilation and curettage (D&C), operative hysteroscopy, and UAE were performed in 16 (33%), 18 (38%), 7 (15%), and 13 (27%) patients, respectively. Two patients with ectopic pregnancies suffered uncontrollable bleeding during D&C and required emergent UAE. Three patients underwent UAE before surgery to prevent hemorrhage. The technical and clinical success rates of UAE were 100%. No complications or recurrences occurred. CONCLUSIONS: UAE is a safe and effective treatment for UAVM-RPOC and a priority for patients with unstable hemodynamics. Conservative management, D&C, and hysteroscopy are safe and effective for patients with UAVM-RPOC with stable hemodynamics. However, UAVM-RPOC following ectopic pregnancy may have high risks of massive hemorrhage during procedures.

A case of hereditary hemorrhagic telangiectasia and literature review.

BACKGROUND: To discuss the clinical features of a patient with hereditary hemorrhagic telangiectasia (HHT). METHODS: The clinical data of one patient with HHT are retrospectively analysed. In addition, we review the relevant literature. RESULTS: A 32-year-old male patient was admitted to the hematology outpatient department of our hospital and presented with intermittent epistaxis for 24 years. In recent years, he was diagnosed with iron deficiency anemia. The nasal endoscopic examination showed telangiectasia at the front of the right-middle turbinate and the left nasal cavity. He had ENG genetic mutation positivity. CONCLUSIONS: Patients with HHT may suffer from many complications, including bleeding, anemia, iron deficiency, and high-output heart failure. These patients may have telangiectasias and arteriovenous malformations in various organs.

Wide-ranging clinical spectrum of paradoxical embolism.

The purpose of this review is to raise the index of suspicion for paradoxical embolism among generalists. The review is based solely on anecdotal reports compiled from EMBASE, MEDLINE, Googlescholar and Pubmed. Search terms were 'paradoxical embolism', 'pulmonary embolism' and 'pulmonary arteriovenous malformations'. What emerged was that right-to-left paradoxical embolism could occur with or without concurrent pulmonary embolism, and also with and without proof of the presence of an 'embolus-in-transit'. Potential sites of single or multiple systemic involvement included the central nervous system, the coronary circulation, renal arterial circulation, splenic circulation, the mesenteric circulation and the limbs. In many cases, the deep veins of the lower limbs were the source of thromboembolism. In other cases, thrombi originated from an atrial septal aneurysm, from a central venous line, from a haemodialysis-related arterio-venous shunt, from a popliteal vein aneurysm, internal jugular vein, superior vena cava, from a pulmonary arteriovenous malformation, from tricuspid valve endocarditis (with and without pulmonary embolism) and from the right atrium, respectively. Stroke was by far the commonest systemic manifestation of paradoxical embolism. Some strokes were attributable to pulmonary arteriovenous malformations with or without coexistence of intracardiac shunts. Clinicians should have a high index of suspicion for paradoxical embolism because of its time-sensitive dimension when it occurs in the context of involvement of the intracranial circulation, coronary circulation, mesenteric circulation, and peripheral limb circulation.

Successful management of an arteriovenous malformation with trametinib in a patient with capillary-malformation arteriovenous malformation syndrome and cardiac compromise.

Capillary malformation-arteriovenous malformation (CM-AVM) syndrome is an autosomal dominant condition characterized by multifocal, noncontiguous pink patches on the skin that often have a surrounding pale halo. In some cases, an association with a fast flow, arteriovenous malformation (AVM) can be identified. Here, we describe a case report of a 16-year-old woman with CM-AVM syndrome and significant cardiac compromise successfully treated with trametinib, a mitogen-activated protein kinase (MEK) inhibitor.

Successful management of a pregnant woman of lower-limb arteriovenous malformation with chronic cardiac failure.

The clinical features of extracranial arteriovenous malformations (AVM) vary from stages I (quiescence) with few symptoms to IV (decompensation) with overt symptoms of cardiac failure. Although the maternal outcomes of pregnant women with extracranial AVM is understudied due to its rarity, previous studies suggested the difficulty in the management of recurrent hemorrhage due to AVM progression during perinatal period; thus, pregnant case of extracranial AVM complicated with cardiac failure were considered challenging. We have reported a woman of stage IV extracranial AVM in the right lower limb with a history of below-the-knee amputation, in which two pregnancies and vaginal deliveries under epidural anesthesia were managed successfully. Cardiac failure did not exacerbate throughout the gestational or postpartum periods. Ulceration gradually worsened, with no massive hemorrhage. It is ideal to assess abnormal vascularity, especially in the lower abdomen, vagina, and epidural and subdural spaces, through magnetic resonance imaging to ensure safe delivery.

Uterine arteriovenous malformation (UAVM) as a rare cause of postpartum hemorrhage (PPH): a literature review.

PURPOSE: Uterine arteriovenous malformations (UAVM) are rare vascular lesions characterized by an abnormal arteriovenous communication between the branches of uterine artery and the myometrial venous plexus. UAVM can be a serious cause of massive post-partum hemorrhage (PPH) leading to potentially life-threatening anemic shock. This review aims to summarize main experiences on clinical presentation and management of UAVM in the setting of unexplained PPH. METHODS: A systematic review of the literature in Scopus, PubMed and MEDLINE was conducted. A case report of a PPH UAVM-related in a patient managed at the authors' center is also provided. RESULTS: Eleven studies met the inclusion criteria. The mean age of cases was 30. In 3/11 cases, previous uterine surgeries were reported and 72.7% cases gave birth by cesarean section. Nine cases had a secondary PPH (24 h up to 12 week post-partum), whereas only one case had a primary PPH. Our case report had both a primary and a secondary PPH. Reported vaginal bleedings were profuse and blood loss entity ranged from 1000 to 2000 ml. In all cases a color Doppler ultrasound was performed first to suspect UAVM and in 10/11 cases a subsequent pelvic angiography confirmed the diagnosis of UAVM as leading cause of the unexplained PPH. In 81.8% cases a conservative management by uterine artery embolization (UAE) was adopted: bilateral UAE was always successful; in 1 out of 2 cases treated by unilateral UEA, emergency total hysterectomy was performed for a sudden hemodynamic instability. CONCLUSION: Maternal mortality pregnancy-correlated is a major health concern worldwide, mostly due by PPH. UAVM should be considered in clinical practice among possible causes of unexplained PPH.